The
internet and several other large and private networks make use of the
DNS or the Domain Name System to direct the traffic online. The DNS
is also popularly called the 'phonebook of the internet'. The
internet makes use of DNS as a name resolution service for public
websites across the world. It refers to a decentralized naming system
that is fit for computer or services that are connected to the
internet or even a private network. Overall, it serves as an
important component for the smooth functioning of internet. When a
user types the name of a site in a browser, the DNS finds the
corresponding IP address for it and any other data required to get
the desired network connection. So a Domain Name System is actually a
friendly way of naming the web servers or the web pages. It defines
addresses to them. They work very similar to an international phone
number and give servers an easy to remember and easy to spell
address. On the other hand, they also hide the IP addresses that are
technical and are not very useful to the viewer as well.

Apart
from all that is mentioned above, the domain system is also
responsible for assigning domain names and mapping those names to the
internet resources by providing name servers
to every particular domain. The internet maintains two different
spaces for names; one is for domain name hierarchy while the second
one is for IP address. It is also important to know here that the
domain name system provides the translation services to and fro on
the internet.

The domain names
are always organized from right to left as is the case in any name (the family names to the right and the personal names to the left.).
These descriptors are actually called 'Domains'.

The TLD or the Top Level Domain, also
called the parent domain is mentioned to the far right of a domain
name; the mid-level domains are obviously in the middle while the
machine name is to the far left. It is often "www". The different
levels of domains are separated by dots or periods.

Some facts about the Domain Name Systems

The main function of the Domain Name System
or the DNS is to store the names and the addresses of the servers of
the public internet. Here are some interesting facts about it:

The
Domain Name Systems is around 30 years old before which a public
system was only identifiable with its host name. The addresses of
all the host names were maintained in one big file. The process
became difficult and complicated in the later years when computer
network grew. It was then that support domains were added and the
single level naming system was changed to the multi level naming
system.

When
DNS was first implemented in 1980, it originally defined only 6
original Top Level Domains that were .com, .edu, .mil, .net, .org
and .gov while there are more than 700 TLDs today on the internet.
The wide expansion for domain names only happened post 2011 with
the basic aim of better classification of the web sites, based on
their purpose.

Currently,
there are more than 100 million domains that are registered under
.com solely. While there are a few that are specifically affiliated
to certain kinds of businesses, there are others that are registered
by individuals for their personal purposes.

DNS
works both in forward and the reverse direction, i.e. the host names
of the web sites and the other internet servers can be converted to
the IP addresses (called the forward DNS look ups) or translating
the addresses to the names (called the reverse DNS look ups). The
reverse DNS lookups are not too common but they are often used in
troubleshooting by the network administrators.

DNS
remains the prime target when it comes to hacking the websites.
Hacking happens when a hacker gets access to the DNS server records
for the website he targets to hack. The hacker access the DNS
records of the website, modifies them in such a way that the
visitors are redirected to some other site. Every time a user visits
a website that is hacked, the DNS instructs the browser to locate
data from a bogus location. It is however, not necessary that the
hackers have to hack into the DNS every time. They can also
compromise with the hosting service of the domain by acting as the
web administrators.

What is WHOIS and WHOIS lookup?

If you are wondering what
is WHOIS? WHOIS is simply read as "who is?"
and is a utility protocol that is used to gain any information on
domain names. The information included is related to the contract and
other technical information on domain name server like the IP address
block and autonomous system which is one of the most crucial roles of
the service. The database content is stored as well as delivered in a
human readable format. Apart from these, there is other additional
information that is related to the status, for instance, if the
domain is locked. To be able to use it, the user needs to enter the
domain in the form and then start with the WHOIS
look up. There might be several events when
the user is not given all the information that is available or even
worse, maybe they are not provided with any information at all. In
such instances, it is important to check if there is any other
alternative to the WHOIS lookup for the domain that is not
responding. There are different levels of the WHOIS lookup protocol
that explain a number of things about the domain name in great
detail. It also decodes several status codes for the user.